The department received word of the vandalism around 6:20 a.m. from the district's transportation department after bus drivers began arriving at work, police said.
The damage, to "numerous buses," was caused by vandals striking the windshields with a blunt object, affecting the driver's view to drive, police said.
The school district decided to enact the one-hour delay for the start of the day, police said.
The incident is under investigation. Anyone with information should contact the North Castle Police Department at 914-273-9500.
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